The present invention relates to a straightening and supporting device for the spinal column in the surgical treatment of scoliotic diseases; the device is removed when the spinal column has healed and comprises a rod-shaped supporting member at least the length of the spinal column area to be treated and tractive members, connected to the supporting member, which exert a straightening and supporting effect on the vertebrae.
Scoliosis means curvature of the spinal column. Scoliosis is a symptom of a disease of which all the basic causes are not yet known. When it becomes more serious it results in deformation of the thorax, which again can have a deteriorating effect on the function of the heart and the lungs. A very great increase in the curvature can shorten the patient's life span. Scoliosis develops most strongly during adolescence.
The treatment methods used for scoliosis have been supporting girdles outside the body, such as the Milwaukee support, and surgical techniques.
In surgical treatment the Harrington rod has been employed which is attached with hooks to two vertebrae on the side of the spines in such a manner that the vertebrae to be straightened are left between the attachment vertebrae. By means of the rod the attachment vertebrae are brought farther apart from each other, whereby the spinal column is straightened. The rod is left to support the patient's back for even several years.
Also known are surgical methods in which springs are attached to the vertebrae or, as in the Dwyer-Sherwood method, a steel cable is attached by means of screws to the bodies of the vertebrae. A force which presses the vertebrae against each other is produced by tightening the cable. The total effect of the force resisting compression and the tractive tension of the cable constitutes the force which straightens the spinal column.
Furthermore, U.S. Pat. No. 3,565,066 describes a device which has a rod-shaped supporting member provided with threaded openings. Tractive members with hooked ends to be attached to the vertebrae have been screwed into these openings.
The above surgical devices have the disadvantage that the straightening force transmitted by the attaching members is concentrated on only a few vertebrae or that the spinal column itself is substantially used as a transmitter of the straightening force. The force applied cannot surpass the strength of the bone of the vertebrae to which the device is attached or the endurance of the weakest intervertebral space. Scoliosis is also associated with the twisting of the spinal column around itself. Forces which correct the twisting of the vertebrae cannot be controlled in an appropriate manner by means of known surgical straightening devices. The patient's incomplete growth in height also sets limitations or requires changes in the installation of the devices.